In such a device in the form of a gas-filled multi-detector, each of the signal electrodes is connected to a separate electrically insulated feedthrough passing through a chamber wall of the detector. On the outer side of the detector, signal lead-out conductors are also connected to the feedthroughs. In practical cases it has been found that, especially if, as in the present case, many feedthroughs are required, irregularities, such as gas leakage, electrical leakage and shortcircuits and the like, often occur. These irregularities are of more frequent occurrence as a feedthrough is used more actively. This may be due both to mechanical and to thermal causes. Corresponding problems occur in devices in which several electrical conductors have to be passed through a vacuum wall. This is the case, for example, in cathode-ray tubes having several electrodes to which electrical potentials are applied or from which electrical signals are derived or to which these signals are supplied.